The genus Rytidosperma in the United States of America.

The genus Rytidosperma is a group of southern hemisphere grasses in the subfamily Danthonioideae. Several species have been introduced in forage trials into regions of the United States, of which 5 have become naturalized in California, Oregon and Hawai‘i in grasslands and ruderal habitats. The species present in the USA are described and new chromosome counts are reported for R. racemosum and R.richardsonii from California, and R. caespitosum from New Zealand.